Contaminated land

Biological remediation concepts are in demand.

Ehemaliges Industriegelände und AbbaugebietImproper treatment of pollutants, as well as leakage from and damage to containers, has caused severe contamination of subsurface environments within the last century. In Germany, a survey by the Federal Environmental Agency found 230.000 sites presumably contaminated with hazardous substances. Exploration and remediation of these sites requires substantial financial resources and thus cost-efficient technologies are needed.

Recently, microbial in situ degradation has been proposed as a viable remediation strategy to eliminate contaminants from groundwater systems. So called monitored natural attenuation (MNA) or enhanced natural attenuation (ENA) are the most-promising strategies for remediation, since they mitigate ecological disturbance and utilize the intrinsic biological capability of the system to degrade compounds within the subsurface. Other attenuation processes such as adsorption, dilution or dispersion will result in a local decrease of pollutant concentrations, but only effectively managed biodegradation will result in a sustainable decrease of contaminants. Therefore, serious expertise is required to demonstrate and quantify in situ biodegradation using MNA- or ENA-remediaton concepts.

Isotopic monitoring provides qualitative and quantitative evidence for biodegradation of many contaminants. As heavy isotopes accumulate within the contaminant-pool throughout the plume, it can be deduced that bacteria are actively purifying the contaminated site. Indeed, the amount of heavy isotope accumulation allows us to quantify the rate of biodegradation activity. Furthermore, a long-term history of biodegradation can be inferred from the isotopic signatures of a few samples.

Our technologies such as BACTRAPs enable sensitive detection of contaminant biodegradation including polycyclic aromatic hydrocarbons (PAHs).